In general, streetlamp devices are lighting fixtures installed along the street to provide safety and security in road traffic. Such streetlamp devices are installed on main roads, roads in business zones and residential zones in suitable forms depending on places thereof. According to the present installation standards of streetlamp devices, when installing streetlamp devices 10 meters above the ground, side illumination occurring in locations 12 meters from right and left sides of a place on the ground, where the streetlamp device is installed, should be 20 lux.
On the other hand, conventional streetlamp devices employ lamps emitting light using the resistance of filaments, which have short lifespans and consume a lot of power. Recently, there have been developed and applied light emitting diode streetlamp devices employing light emitting diode (LED) lamps as light sources, the LED lamps having lifespans longer than those of the lamps employing filaments, the efficiency of the LED lamps being high.
On the other hand, as shown in FIG. 1, a general LED streetlamp device 100 includes a body frame 130 with LED lamps 110 attached as light sources and a reflective plate 120 reflecting light from the LED lamps 110 toward an area directly below or a peripheral area; and a transmission plate 140 manufactured using transparent glass or transparent plastic covering the LED lamps 110 and the reflective plate 120 attached to the body frame 130. Also, on top of the body frame 130, there is provided a fastening portion 150 formed in the shape of a bar or a pipe. Accordingly, the LED streetlamp device 100 may be attached and installed to a connecting bar 210 of a lamppost 200 by coupling the fastening portion 150 therewith using a general coupling member 220 formed of one of a bolt, a nut, and a bracket.
Also, the connecting bar 210 of the lamppost 200, coupled with the fastening portion 150, is formed in the shape of a bar with a certain diameter. However, in some cases, as an example, when providing a shielding member 230 for protecting the streetlamp device 100 together with the connecting bar 210 formed in a single body, as shown in FIG. 2, the connecting bar 210 may have an extended diameter of an end thereof. In this case, the fastening portion 150 of the LED streetlamp device 100 is also designed according to the extended diameter of the connecting bar 210.
Referring to FIG. 2, a reference numeral 210a indicates an extended diameter portion of the connecting bar 210 and a reference numeral 150a indicates an extended diameter portion of the fastening portion 150. Also, in FIG. 2, for example, the extended diameter portion 150a of the fastening portion 150 is coupled with the extended diameter portion 210a of the connecting bar 210 by a screw-connection.
However, since the LED streetlamp device 100 employs a plurality of LED lamps as a light source, heat of a high temperature is emitted according to driving the LED lamps and there occurs damage to diodes, but there has been no effective solution for occurrence of the heat with a high temperature.